Mobile networks have recently developed from 3G to LTE (Long Term Evolution). Meanwhile, traditional 2G and 3G mobile networks are still in use. Therefore, LTE mobile phones are required to be capable of covering multiple frequency bands including 2G/3G/4G. Accordingly, a very wide mobile phone antenna band width is required. However, size of mobile phone motherboards are limited. Therefore, available space for a mobile phone antenna is also limited. Furthermore, a traditional mobile phone antenna cannot be used satisfactorily to cover different frequency bands as required, and, particularly, cannot realize low frequency bandwidth-intensive coverage.
As shown in FIG. 1, an antenna part of a traditional mobile phone radio frequency front end includes a main antenna and a matching circuit thereof, wherein the main antenna is controlled by a main antenna switch to switch between different frequency bands. Logic of the main antenna switch is generally set by a radio frequency hardware engineer together with a radio frequency software engineer.
In order to enable a mobile phone antenna to cover a wider frequency range, researchers have proposed adding a parasitic antenna on a traditional mobile phone antenna. However, it has been found in tests that, even if a frequency band coverage requirement is fulfilled, antenna performance requirement is very difficult to satisfy. Particularly, when covering a low frequency bandwidth-intensive of 700 M (LTE Band12, B17 and the like)—960 MHz (GSM900, WCDMA Band8), antenna performance requirements are difficult to satisfy.
Therefore, the prior art still needs to be improved and developed.